Control system for container manufacturing apparatus

ABSTRACT

Improved device for sensing and replenishing fluid losses in selected portions of a closed fluid driving circuit within which a piston is mounted, said piston having at least one punch means attached to each side thereof so as to effectively regulate the amount of travel of the piston in either direction at all times as well as the punches attached thereto.

Unite a: tee a emit n 1 ammo Inventors A. Dean Smith, also known asArthur Dean Smith, San Lorenzo; Fred R. Waechter, Oakland both of,Calif. Appl. No. 859,997 Filed Sept. 22, 1969 Patented Aug. 17, 1971Assignee Kaiser Aluminum 8; Chemical Corporation Oakland, Calif.

CONTROL SYSTEM FOR CONTAINER MANUFACTURING APPARATUS 16 Claims, 1Drawing Fig.

U.S. Cl r. 72/349, 72/432 Int. Cl ..]B2ld 22/20, B21j 7/ 1 2 Field ofSearch 72/347- [56] References Cited UNITED STATES PATENTS 2,766,59010/1956 Erwin et al 60/545 3,040,533 6/1962 Heinrich 60/545 3,167,0441/1965 Henrickson 72/349 3,314,274 4/1967 Langewis 72/349 3,353,39411/1967 Smith 72/347 3,457,766 7/1969 Langewis et al.. 72/432 PrimaryExaminer-Richard J. Herbst Azlorneys-James E. Toomey, Paul E. (Calrow,Harold L.

Jenkins and John S. Rhoades ABSTRACT: Improved device for sensing andreplenishing fluid losses in selected portions ofa closed fluid drivingcircuit within which a piston is mounted, said piston having at leastone punch means attached to each side thereof so as to effectivelyregulate the amount of travel of the piston in either direction at alltimes as well as the punches attached thereto.

9s 94' mo X l i CONTROL SYSTEM FOR CONTAINER MANUFACTURING APPARATUSBACKGROUND OF 'THE INVENTION Various schemes have been proposed in thepast such as that shown particularly in U.S. Pat. No. 3,457,766; whichissued July 29, 1969, for making container bodies by the draw and ironprocess and wherein a common driving or actuating piston is mounted in aclosed fluid circuit along with a crank driven yoke device. At least onedraw and iron punch means'is attached to each side of the common drivingpiston and a fluid makeup system for the closed fluid circuit is alsodisclosed. This makeup system operates to eliminate unbalanced strokingof the actuating or slave piston by continually monitoring and adjustingwhen necessary the fluid volumes on opposing sides of the slave piston.

The instant fluid makeup system, while employing the basic principles ofthe fluid makeup system of the aforementioned patent, constitutes animprovement thereover in that the instant system eliminates certain ofthe elements of the prior system and thus provides for a more simplifiedand more overall trouble-free control system in lieu thereof.

SUMMARY OF THE INSTANT lNVENTlON Accordingly, it is the primary purposeof the instant invention to provide an improved container manufacturingapparatus particularly of the draw and iron type wherein the properstoking of the punch means attached to each of the opposing sides ofacommon drive piston is effected by a unique control arrangement. Thisarrangement reliably and smoothly controls the stroke of the commonactuating piston at all times in a manner that constitutes animprovement over that shown in the aforesaid U.S. Pat. No. 3,457,766. Asa result, underor overtravel of a punch means through its associateddies is in hibited. In effect, the equipment is set to function at alltimes in a unique, self-correcting fashion.

BRlEF DESCRlPTlON OF THE DRAWINGS The drawing is a schematic view withparts removed of the fluid actuating and control system for a containerforming apparatus as well as the container forming apparatus in whichthe improved makeup or drift control device of the instant in vention isincorporated.

With further reference to the drawing, the container forming apparatusembodying the improved control system of the instant invention generallycomprises an overall housing 12 that includes, as in the case of thedevice of U.S. Pat. No. 3,457,766, a prime mover or power unit 14comprised of a crank arm shaft 16 connected to a pair of crank arms 18,only one of which is shown in dotted lines. Crank arms 18 are disposedon opposing stub journals, only one of which is shown at 20. Thejournals are mounted in appropriate bearings and are adapted to berotatably driven by a drive wheel 21 in a conventional fashion. As thedrive wheel rotates, it causes movement of shaft 16 located in andconnected to slide fitting 22. At the same time slide fitting 22 movesup and down in the hollowed-out interior 24 ofa double-acting yoke 26,it causes corresponding movement of drive yoke 26 to the left or to theright in cyclic fashion whereupon left and righthand pistons 28 and 30connected to yoke 26 will also be correspondingly moved forward andbackward. As these pistons are forced forward and backward, they willact upon the fluid, such as hydraulic fluid, contained in the closedfluid circuit made up principally of the fluid in fluid-containingchambers 32 and 34 on opposing sides of a common actuating or slavepiston 36, and the interior chamber 38 of elongated cylinder 40 forpiston 36 located at the top of housing 12. Attached to each of theopposing sides of actuating piston 36 is an elongated piston rod 42. Oneor more forming rams or punches 44 are suitably connected, such as in aforklike manner, to the outer free end of each piston rod 42. With thefluid in chamber 38 and chambers 32 and 34 forming a common fluidcircuit, slave or driving piston 36 is thus disposed in one portion ofthe circuit and yoke 26 in another portion of the circuit. Punches 44are adapted to be passed along with cupshaped workpieces to be drawn andironed through their associated tool packs schematically indicated at 45and made up of various die elements of the type shown and described, forexample, in U.S. Pat. No. 3,399,558 to Langewis et al. granted on Sept.3, 1968.

Chambers 32 and 34 are further provided with an overload fluid-filledbypass 46, which includes poppet valve assemblies 48, for bringing thebypass into fluid intercommunication with chambers 32, 34 and 38whenever one of the rams 44 encounters an obstruction, all as set forthin; detail in the aforementioned U.S. Pat. No. 3,457,766.

Unbalanced stroking of common actuating piston 36 occasioned by thedrifting of piston 36 to the left or right in chamber 38 as a result ofleakage in the closed fluid circuit and the resultant overandunder-stroking of punches 44 is automatically corrected in an improvedfashion by the im' proved control system of the instant invention.

This control system includes a makeup pump 50, driven by a motor 52.Pump 50 forces hydraulic fluid, such as oil, at a pressure usually onthe order of 4050 p.s.i., to pass from a tank or reservoir 54 through amain line 56 and branch conduits 58 and 53a and 60 and 60a to chambers34 and 32 of housing 12 respectively and past one-way check valve 88 inline 58 and valve 90 in line 60. A relief valve 62 is connected acrossmain line 56 by way of conduit 64 and releases excess fluid from line 64into exhaust line 66 and to the reservoir 54. Although not shown, it isto be understood as indicated in U.S. Pat. No. 3,457,766 that the mainline of pump 50 can be connected to various bearings for the crank arms18 and various bearings for the yoke element 26 so as to adequatelylubricate all of these bearings during continuous operation of theapparatus. If desired, an appropriate filter 68 can be incorporated inmain line 56 on the inlet side of pump 50. Thus pump 50 in cooperationwith check vallves 88 and 90 serves to maintain pressure fluid at thedesired predetermined pressure level in chambers 32, 34 and 38 duringoperation of the container forming apparatus even though fluid underpressure tends to leak from chambers 32, 34 and 38 of housing 12, andpast pistons 28 and 36 of yoke 26 and in between a piston rod 42 and theopenings therefrom in portions of overall housing 12. Continuousmaintenance by makeup pump 50 of the fluid under pressure at apredetermined level in chambers 32, 34 and 38 advantageously assuresproper performance of the control system of the instant invention aswill be more fully discussed hereinafter.

In an advantageous embodiment of the instant invention, each one of thepair of fluid replenishing circuits 70 for the main closed fluid circuitis not only interconnected to pump 50, but also to each other as well asbeing individually interconnected to a chamber 32 or 34, as the case maybe, on opposite sides of double-acting actuating piston 36. Inasmuch aseach fluid replenishment circuit 70 is made up of l ke parts, adescription ofone such circuit will generally suffice for both.

A fluid replenishing circuit 70 is generally comprised of a fluidreplenishing and displacement chambered device 74, four way two positionvalve 76, and a pair of solenoids 78 for selectively positioning thevalve in one of its two positions. A check valve 84 is disposed inbranch conduit between valve 76 and branch conduit 58a for the left-handfluid replenishing circuit 76, and a check valve 86 is disposed inbranch conduit 82 between valve 76 and branch conduit 60a for therighthand fluid circuit 70, all as indicated in the drawing.

The fluid chamber device 74 of each fluid replenishing circuit 70generally comprises a hollow cylinder 92 closed off at its oppositeends. A piston element 94 is disposed within the cylinder and anapertured piston bearing element 96 is intermediately disposed betweenthe ends of the cylinder for bearingly supporting piston element 94during its reciprocation between the ends of cylinder 92. Although fluidreplenishing device 74, is illustrated as having a reciprocating piston94, other types of fluid replenishing devices 74 could be used, such asa rotary fluid displacement device, the vanes of which could be movablein clockwise or counterclockwise directions.

In order to automatically actuate a fluid replenishing circuit 70 inresponse to an unbalance in the stroke of piston 36, a

sensor control circuit advantageously ties in the pair of solethe usualinput'lines 102, the outer terminal ends of which are I usuallyconnected to a 60-cycle AC source (not shown).

Sensor 103 of each circuit 70 is affixed to the framework (not shown) ofthe apparatus a predetermined distance back from the point identified bya dotted reference line 105 that would be the normally retractedposition of the punch or punches 44 with which it is associated whilebeing in radial alignment with a piston rod 42 to which the same ram orrams 44 are connected. During the normal return stroke of a given pistonrod 42, the punch or series of punches 44 associated therewith will bereturned to a retracted or rearwardmost position as indicated byreference line 105 therefor in the drawing. 7

Sensor 103 connected to its associated amplifier 97 by a lead 104 can beof the type generally sold by Peco, Corp. of Mountain View, California,and commercially identified by Model No. A- 3 140 for generating anelectromagnet field F in a general direction at right angles to thelongitudinal axis of a piston rod 42.

Since a piston rod 42 and the rams 44 associated with a given sensor 103are of an electrically conductive material, such as a suitable grade ofsteel, the sensor 103 can be minutely adjusted whereby piston rod 42 andrams 44 will induce a certain selected counterreactance in the sensor103 during relatively small ou't-of-balance or drifting movements ofpiston rod 42 during the reciprocation thereof. Thus, if thedoubleacting piston 36 is balanced relative, to reciprocal movements ofyoke 26 and does not deleteriously drift to the right or left, theresultant reciprocal movements of a piston rod 42 and its associatedmonitoring sensor 103 will not operate to induce acounterreactance'signal in the sensor for transmission to amplifier 97through lead 104. However, if the stroking of the double-acting piston36 becomes unbalanced relative to reciprocal movements of yoke 26 due tofluid leadage in any part of the system, the movements of a piston rod42 will be correspondingly unbalanced whereby the inner edge portions oframs 44 will enter a greater part of field F ofa given sensor 103associated with a given piston rod 42 depending upon which side of theclosed fluid circuit has lost fluid and have a retracted position alongthe dotted lines 107 in the drawing rather than line 105.

Such entrance .of the inner portions of the rams into a greater part-ofa field F generated by a sensor 103 during an unbalanced stroke ofpiston rod 42 induces the desired greater counterreactancein the sensorso affected. This causes the sensor to generate and transmitandelectrical signal through its associated lead 104 to its amplifier 97in a fluid replenishing circuit 70. It has been found that, if in theinitial positioning of sensor l03 the forward end ofa sensor 103 islaterally or radially outwardly spaced by a gap Y on'the order ofone-sixteenth inch away from the surface of the associated rod 42 and atthe same time is spaced in an axial direction inwardly of the normalretracted position of the associated rams 44 by a clearance X on theorder of one-fourth inch, sensor 103 will not interfere with the normaloperation of the draw and iron forming apparatus but will still detectunbalanced stroking of its associated piston rod 42.

As indicated in the drawing, each piston 28 or 30 of yoke element 26 isadvantageously of a substantially larger diameter than pistonlikeelement 94 of each fluid displacement and replenishing chamber device 74as well as being of larger diameter than piston 36. The strokemultiplier concept involved herein advantageously contributes to thecontrol system of the instant invention for uniquely transferring excessfluid from one side of piston 36 to the opposite and fluid defi- I cientside thereof whenever an unbalancing of piston 36 -oc-. curs as a resultof the unequal amounts of fluid on the oppos- I ing sides of piston 36,during operation of the apparatus as will be described below. I

It is to be understood, of course, that the pressure of the fluid movedby pistons 28 and 30 upon reciprocation of the yoke 26 in the closedfluid circuit is greater than the pressure of the fluid being moved bypump 50. Consequently, check valve 88 connected to chamber 34 by line58a and check valve 90 connected to chamber 32 by line 60a will remainautomatically closed when yoke 26 reciprocally moves to the right or tothe left, thereby correspondingly isolating the fluid lines 60 I I and58 containing fluid under pressure and connected to pump 50 from thepressure fluid located in the chambers 34 and 32 containing pistons 28and 30. v I

Operation of control systems will now be described. Let us assume thatactuating piston 36 has overtravelled to the right in the drawing due toa leakage of fluid from right main chamber 34 during leftward strokemovement of yoke 26.

When this occurs, the inner extremity of a left-hand ram 44 will pass tothe right of left-hand reference line 105 and enter the associated fieldF in such fashion so as to induce a counterreactance in left-hand sensor103 shown in the drawing. ln-

duction of this reactance in sensor 103 results in sensor 103generatingand transmitting a signal through its lead l04 to itsamplifier 97 in the left-hand replenishing circuit 70. The signal fromsensor 103 will cause this left-hand amplifier'97 to generate andtransmit a signal through one of its leads, such as lead 100, toenergize the right-hand solenoid 78 for valve 76in the left-handreplenishing circuit 70, as viewed in the drawing. Right-hand solenoid78 will then operate the valve spool of valve 76, whereby valve portsBand C of valve 76 are interconnected at the same time ports A and D areinterconnected.

With left-hand valve 76 in this position, fluid from chamber 32andactivated as a result of the leftward stroke movement of yoke 26 andpiston 28 can be passed from chamber 32 through lines 60a and 82 intovalve 76 through ports B and C and then through line 81 and against theleft side of piston 94 and the left-hand winged elements 94 affixed topiston 94. By

virtue of piston 28 being of a substantially larger diameter than pistonwinged elements 94', the activated fluid under pressure from chamber 32causes movement of piston 94 in chamber 74 proportionately a greaterdistance to the right for I a small incremental leftward movementofpiston 28 until the right end of piston 94 abuts the right endofleft-hand cylinder 92. Piston 94 upon its movement to the righteffects passage of fluid out of cylinder 92, line 84 and left-hand valve76 by way of ports A and D.

The fluid then passes check valve 84 which is ir ctive due to theleftward movement of piston 30 of yoke 26, and then moves throughleft-hand valve line 80 and line 58a into the fluid deficient chamber34. This transfer of activated flu.

' underpressure from chamber 32 to the left side of left-hand cylinder92 and the resultant transfer of activated fluid under pressure from theright side of left-hand cylinder 92 to the fluid deficient chamber 34all involve a certain time period even though relatively small. Thistime period is normally somewhat longer than and overlaps the overalltime it takes n for a full stroke movement of yoke 26 to the left orright as indicated in the drawing. Thus, activated fluid under pressurefrom the right side of left-hand replenishing device 74 is usually beingadmitted to fluid deficient chamber 34, when I yoke piston 30 startsmoving to the right for activating the fluid of fluid deficient chamber34. In view of the fact that at this time the activated fluid underpressure from the right end of left cylinder 92 is at a higher pressurelevel than the activated fluid under pressure within fluid deficientchamber 34 during the immediate return rightward stroke of yoke 26, thereplenishing fluid from the right end of left-hand cylinder 92 can enterand refill fluid deficient chamber 34 thereby resulting in an immediaterebalancing of an unbalanced stroke of piston 36 to the right.

Further, since the volume of the activated replenishing fluid from theright end of left-hand cylinder 92 is substantially less than the volumeof fluid within fluid deficient chamber 34, the volume of activatedreplenishing fluid admitted to chamber 34 will be immediately absorbedby the larger volume of the fluid therein without adversely affectingthe reciprocal stroking of yoke 26 and the rebalancing of an unbalancedstroke of piston 36. At the same time, left-hand piston 94 operates toreplenish chamber 34, the right-hand replenishing circuit 70 isautomatically disconnected from chamber 32 by virtue of the oneway checkvalve 86 therefor as well as check valves 88 and 90, thus forcing fluidfrom chamber 32 to operate the left-hand plunger 94 only.

As soon as the balancing of the piston stroke for piston 36 occurs andthe punches 44 operate properly, the counterreactance of a left-hand ram44 on its sensor 103 disappears because the ram or rams fail to pass tothe right of the normal left-hand retraction line 105. Although theright-hand solenoid 78 for left-hand valve 76 drops out along withleft-hand sensor 103 upon the disappearance of any counterreactance, thevalve setting for left-hand valve 76 will remain the same, i.e., ports Aand D are connected, while ports B and C remain connected.

In an advantageous embodiment of the invention, each amplifier 97 isstructured and electrically connected to the left and right-handsolenoids 78 for its associated valve 76 in a manner well known in theart whereby it functions to transmits a signal impulse and triggeralternately first one solenoid 78 and then the other solenoid, e.g.,first the right solenoid and then the left, each time a separate orindividual signal is generated by a sensor 103.

Thus, as noted above in the case ofa left-hand ram 44 being forced pastthe normal retraction line 105 due to a deficiency in the fluid volumeon the right-hand side of piston 36, a signal was passed to amplifier 97of left-hand circuit 70 to operate the right-hand solenoid thereofwhereby valve ports B and C were interconnected at the same time ports Aand I) were interconnected.

This condition of the valve spool remains until on the next successivesignal from the same sensor 103 on the left-hand side of the apparatusthe left-hand solenoid for left-hand valve 76 is triggered and operatesto move the valve spool to connect ports A and C and ports B and D. Inother words, sensor 103 and its associated amplifier 97 act as anoverall, simple flip-flop-type switch. This will allow activated fluidunder pressure again from line 60a to pass as before through line 82into valve 76 through ports B and D and through line 83 into the rightend of chamber device 74 in order to effect movement of piston 94 to theleft so as to pump activated fluid under pressure at a greater pressurelevel than the activated fluid from chamber 32 out through line 81 andthrough ports C and A of valve 76 into lines 80, and 58a and into thefluid deficient chamber 34 to replenish the volume of fluid in this partof the circuit and bring about a rebalancing in the stroking ofthepiston 36 in the fluid circuit.

Just as in the case of where piston plunger 94 of the lefthand device 74previously moved to the right during a prior overstroking of piston 36to the right, right-hand replenishing circuit 70 is automaticallydisconnected or isolated from chamber 32 by check valve 86 in line 82during the successive uctuations of lefthand valve 76. Thus, for anyovertravel of actuating piston 36 to the right as viewed in the drawing,the proper amount of piston balancing restoration fluid under pressurewill be directed through lines 60a and 82, and valve 76 to either sideof replenishing chamber 74 so as to effect advancement of piston 94toward one end of left-hand device 74 in order to pump a predeterminedamount of replenishing fluid from left-hand device 74 to replenish thefluid loss in chamber 34 by way of conduit 81 or 83, valves 76 and 84and conduits and 58a. In other words, a valve 74 is always in a readycondition to supply fluid lost: in one of the chamber circuit portions32 or 34.

Conversely, if there is an overtravel of actuating piston 36 to theleft, whereby a right-hand punch 44 will pass to the left of theright-hand dotted reference line 105 in the drawing and up to referenceline 107, portions of a ram 44 associated with the right sensor 103 willinduce a greater counterreactance therein. Induction of a greatercounterreactance causes generation and transmission of a signal from theright-hand sensor 103 through lead 104 to amplifier 97 of the right-handreplenishing circuit. The transmitted signal from right-hand sensor 103causes right-hand amplifier 97 to transmit a signal through conductor 98or depending on the specific signal generating condition of amplifier 97in order to effect energization of right or left'hand solenoid 78 forright-hand valve 76. Energization, for example, of the right-handsolenoid 78 causes the valve spool of valve 76 to place valve ports Aand C in fluid interconnection at the same time ports B and D of thevalve are connected. With valve port A connected to port C and port B toport D in the valve of right-hand circuit 70, activated fluid underpressure from chamber 34 is directed to the left-hand end of fluid pumpdevice 74 through lines 58a, 80 and 81 to advance piston 94 in theright-hand pump device 74 to the right as indicated by dotted arrowlines in the drawing. This rightward advancement of piston 94 causesdisplacement from pump chamber device 74 in the right-hand replenishingcircuit 74 of a predetermined amount of replenishing fluid at anactivated pressure level greater then the activated pressure of excessfluid from chamber 34. This replenishing fluid is then admitted tofluid-deficient chamber 32 through check valve 86 and aligned ports Band D of valve 76 and lines 83, 82 and 60a.

Left-hand replenishing circuit 70 is at the same time automaticallydisconnected from chamber 34 by virtue of check valve 84 therein beingsubjected to fluid under pressure from chamber 34 through lines 58a and80 during an overstroke of piston 36 to the left as viewed in thedrawing.

Whenever piston 36 overstrokes to the left again, an inner portion ofaram 44 associated with the right-hand sensor 103 operates to induce afurther counterreactance in the righthand sensor 103, all asaforedescribed. This results in generation and transmission of a signalfrom right-hand sensor 103 to right-hand amplifier 97 through lead 104.The set condition of right-hand amplifier 97 will now be such in view ofthe initial assumption made above as to its first set condition that itwill transmit a signal to the left-hand solenoid 78 through lead 98 ofright-hand replenishing circuit 70 in order to effect energization ofleft-hand solenoid 78 for the right-hand valve 76. Such energization ofleft-hand solenoid 78 causes a leftward movement of the right-hand valve76 thereby connecting valve port A to D and B to C, all as dicated inthe drawing. By virtue of fluid under pressure within chamber 3 4 beingactivated when piston 36 overstrokes to the left in the drawing, theexcess fluid under pressure is directed from chamber 34 to the right endportion of pump device 74 of right-hat. replenishing circuit 70 throughlines 58a, 80 and 83 and aligned ports A and D of valve 76.

Fluid in the right end of chamber 92 causes right-hand pump piston 94 tobe displaced to the left as indicated by the solid arrow line in thedrawing thereby displacing a predetermined amount of activated fluidfrom the left end of the pump device at a greater pressure level thanthe activated fluid from chamber 34. This replenishing fluid is thenadmitted to fluid circuit chamber 32 through aligned ports B and C ofvalve 76 and check valve 86 and lines 81, 82, 60a so as to replenishfluid lost from chamber 32 as the result of an overstroking of piston 36to the left. At the same time, left replenishing circuit 70 isautomatically disconnected from chamber 34 by virtue of closure of checkvalve 84 in the manner aforedescribed.

In view of the foregoing, it is evident that fluid pump device 74 of theright-hand replenishing circuit 70 automatically compensates for anyfluid lost in chamber 32 and that both replenishing circuits 70 areexceptionally sensitive to changes in the fluid volumes of variousportions of the closed circuit.

By use of the instant control system, it is evident that a simple andreliable monitoring arrangement is provided for sensing and correctingthe unbalanced stroking or drifting of the actuating or slave piston 36in either direction so that accurate stroke control of all forming rams44 on the apparatus is assured at all times. Unbalanced stroking issubstantially instantaneously corrected by virtue of the ready conditionat all times of each valve 76 due to its actuation by its associatedsensor 103 and amplifier 97. In other words, the leftand right-handfluid replenishing circuits 70 effectively cooperate with each other andthe closed fluid circuit in a substantially instantaneous automatic andsmooth fashion to compensate for overtravel of the actuating piston 36either to the right or left. As the result of the instantaneousoperation, smoothness and reliability of fluid replenishing circuits 70of the control system of the instant invention, quality control of drawnand ironed thin-walled metal cans, such as aluminum or steel cansproduced by multiple rams 44, can be effectively maintained even whenactuating piston 36 is repetitively stroked on the order of 120 or morestrokes per minute.

Since electromagnetic sensor 103 involves no moving mechanical parts,the magnetic field F of the sensor immediately detects a greatercounterreactance when a ram associated with the field enters a greaterpart thereof due to an overstroking of the ram as aforedescribed andinstantaneously brings about the generation and transmission of theproper correcting signal to other parts of the device.

All of this in turn means that the equipment can be operated at veryhigh production speeds because of the sensitivity and operating speedsof the piston balancing circuits 70.

Chambers 32, 34, 46 and 38 are initially filled with fluid by the use ofa pair of bleed valves 106 connected to the top of housing 12 throughconduits 108 on opposite sides of actuating piston 36. Conduits 110,however, can operate to exhaust the bled fluid from valves 106 toreservoir 54. Fluid replenishing and pump devices 74 of both circuits 70include ap propriate bleed valves (not shown) at opposite ends thereoffor assuring proper filling of devices 74 prior to operation of thecontrol system of the instant invention.

It is to be understood that although the control system has beendescribed in connection with the use of certain media, such aselectrical signals for selectively directing excess and activated fluidunder pressure from one chamber in order to effect admittance ofactivated fluid to a lost fluid chamber, e.g., as from 34 to 32 in themanner aforedescribed, during an overstroking of actuating piston 36,the control system could readily use a fluidic-type sensor in lieu ofeach electromagnetic sensor 103 to generate and transmit electricalpulses to amplifiers 97.

Advantageous embodiments of the invention have been shown and described.It is obvious that various changes and modifications may be made thereinwithout departing from the scope thereof as defined in the appendedclaims, wherein:

What we claim is:

1. An apparatus for forming a deep drawn seamless can body provided witha bottom and sidewall formed integrally therewith comprising a closedfluid circuit, an actuating piston mounted in one portion of said fluidcircuit and at least one separate forming punch secured to each of theopposing sides of said piston, drive means located in another portion ofsaid circuit for activating the fluid in said closed fluid circuit andthe said piston so as to alternately urge first one of said punches in asingle uninterrupted stroke thereof through the die means associatedtherewith and then an opposing punch in a single uninterrupted stroke ofthe last-mentioned punch through the die means associated therewith,means for replenishing fluid lost on one side of said piston and in aselected portion of the closed fluid circuit said lost fluid resultingin an unbalancing of the stroke of said piston, said fluid replenishingmeans including a fluid pump device connectable to the fluid deficientportion of the fluid circuit for supplying fluid to said fluid deficientportion of the fluid circuit, means including a valve means for fluidlyconnecting said fluid pump device directly to another portion of theclosed fluid circuit so as to actuate said pump device and therebysupply fluid to said fluid deficient portion of the fluid circuit and asensor means activated by an overstroked punch for operating said valvemeans to connect said pump device simultaneously to the said differentportions of said closed fluid circuit.

2. An apparatus as set forth in claim 1 including an amplifier meansconnected to said sensor means.

3. An apparatus as set forth in claim 1 in which said drive means iscomprised of a pair of oppositely disposed pistons connected to adriving yoke.

4. An apparatus as set forth in claim 2 wherein said valve means isoperated by solenoids controlled by said amplifier means.

5. ln'an apparatus as set forth in claim 1 wherein said sensor means isan electromagnetic sensor means.

6. An apparatus as set forth in claim 1 including a pair of fluid pumpdevices, each of said devices being operable to supply fluid lost from adifferent selected portion of the fluid circuit to said differentselected portion of the circuit and each of said pump devices beingoperated by a different valve means controlled by a separate sensormeans.

7. An apparatus as set forth in claim 1, including a pump for keepingsaid first-mentioned pump device fully primed.

8. In an apparatus for forming a deep drawn seamless can body providedwith a bottom and sidewall formed integrally therewith, the combinationof a closed fluid circuit, an actuating piston mounted in one portion ofsaid fluid circuit and at least one separate forming punch secured toeach of the opposing sides of said piston, yoke-type drive means locatedin another portion of said circuit for reciprocating'the fluid in saidclosed fluid circuit and the said piston so as to alternately urge firstone of said punches in a single uninterrupted stroke of the punchthrough the die means associated therewith and then an opposing punch ina single uninterrupted stroke of the last-mentioned punch through thediemeans associated therewith, means for replenishing fluid lost on eachside of said piston in the closed fluid circuit, the lost fluid oneither side of said piston in the closed fluid circuit resulting in anunbalancing of the stroke of said piston, said fluid replenishing meansincluding a pair of fluid displacement pump devices, one pump devicebeing directly connectable to a portion of the fluid circuit on one sideof said piston and the other displacement pump being directlyconnectable to the portion of the fluid circuit on the other side ofsaid piston, separate valve means for fluidly connecting each pumpdevice separately and directly to a different side of said yoke-typedrive means simultaneously with connecting a given pump device to afluid deficient portion of the fluid circuit so as to separatelyactivate each of said pump devices, a sepai. e sensor means on each sideof the apparatus and activated by a given verstroked punch forselectively and separately operating one of said valve means so as toconnect a selected one of said pump devices to one side of saidyoke-type drive means simultan. ously with connecting saidlast-mentioned pump device to a fluid deficient portion of the closedfluid circuit.

9. An apparatus as set forth in claim I in which said yoke drive meansincludes a drive piston at each side of thc voketype drive means, eachdrive piston being in direct contact with the fluid in a given portionof said closed fluid circuit in order to effect reciprocation of thefluid in the closed circuit and reciprocation of said actuating piston.

10. An apparatus as set forth in claim 9 in which each displacement pumpdevice includes a pump piston which has a smaller diameter than a drivepiston attached to said yoketype drive means.

1 1. An apparatus as set forth in claim 8 in which said sensor means areelectromagnetic sensor means.

12. An apparatus as set forth in claim 8 including oppositely disposedsolenoid means operated by a sensor means for controlling each of saidvalve means and keeping said valve means in a ready condition at alltimes.

13. An apparatus as set forth in claim 8 including a further valve meansfor isolating one pump device from the fluid circuit when the other pumpdevice is operating.

14. An apparatus for forming a deep drawn seamless can body providedwith a bottom and sidewall formed integrally therewith and comprising aclosed fluid circuit, a piston means mounted in one portion of saidfluid circuit, at least one separate forming punch means secured to eachof the opposing sides of said piston means, yoke means located inanother portion of said circuit for cyclically activating portions ofthe fluid in said closed fluid circuit in order to actuate said pistonmeans so as to alternately urge first one of said punch means in asingle uninterrupted stroke of the punch means through a die meansassociated therewith and then an opposing punch means in a singleuninterrupted stroke of the last-mentioned punch means through the diemeans associated therewith,

llll

means for replenishing fluid lost on one side of said piston means andin a selected portion of the fluid circuit, the said lost fluid on theone side of said piston means causing an unbalanced stroke thereof, saidreplenishing means including a sensor operatively associated with apunch means for detecting an overstroked punch means upon a fluiddeficiency, the improvement comprising a sensor operated valve means forfluidly connecting a fluid pump device directly to a fluid activatedportion of said fluid circuit simultaneously with connecting the samepump device to the fluid deficient portion of the fluid circuit wherebysaid pump device can in rapid fashion supply fluid to the fluiddeficient part of the circuit upon the fluid deficiency being detected.

15. An apparatus as set forth in claim 14 wherein said sensor is anelectromagnetic sensor.

16. An apparatus as set forth in claim 14 including an amplifier meansinterconnecting said valve means and said sensor for placing said valvemeans in a ready condition at all times.

1. An apparatus for forming a deep drawn seamless can body provided with a bottom and sidewall formed integrally therewith comprising a closed fluid circuit, an actuating piston mounted in one portion of said fluid circuit and at least one separate forming punch secured to each of the opposing sides of said piston, drive means located in another portion of said circuit for activating the fluid in said closed fluid circuit and the said piston so as to alternately urge first one of said punches in a single uninterrupted stroke thereof through the die means associated therewith and then an opposing punch in a single uninterrupted stroke of the last-mentioned punch through the die means associated therewith, means for replenishing fluid lost on one side of said piston and in a selected portion of the closed fluid circuit said lost fluid resulting in an unbalancing of the stroke of said piston, said fluid replenishing means including a fluid pump device connectable to the fluid deficient portion of the fluid circuit for supplying fluid to said fluid deficient portion of the fluid circuit, means including a valve means for fluidly connecting said fluid pump device directly to another portion of the closed fluid circuit so as to actuate said pump device and thereby supply fluid to said fluid deficient portion of the fluid circuit and a sensor means activated by an overstroked punch for operating said valve means to connect said pump device sImultaneously to the said different portions of said closed fluid circuit.
 2. An apparatus as set forth in claim 1 including an amplifier means connected to said sensor means.
 3. An apparatus as set forth in claim 1 in which said drive means is comprised of a pair of oppositely disposed pistons connected to a driving yoke.
 4. An apparatus as set forth in claim 2 wherein said valve means is operated by solenoids controlled by said amplifier means.
 5. In an apparatus as set forth in claim 1 wherein said sensor means is an electromagnetic sensor means.
 6. An apparatus as set forth in claim 1 including a pair of fluid pump devices, each of said devices being operable to supply fluid lost from a different selected portion of the fluid circuit to said different selected portion of the circuit and each of said pump devices being operated by a different valve means controlled by a separate sensor means.
 7. An apparatus as set forth in claim 1, including a pump for keeping said first-mentioned pump device fully primed.
 8. In an apparatus for forming a deep drawn seamless can body provided with a bottom and sidewall formed integrally therewith, the combination of a closed fluid circuit, an actuating piston mounted in one portion of said fluid circuit and at least one separate forming punch secured to each of the opposing sides of said piston, yoke-type drive means located in another portion of said circuit for reciprocating the fluid in said closed fluid circuit and the said piston so as to alternately urge first one of said punches in a single uninterrupted stroke of the punch through the die means associated therewith and then an opposing punch in a single uninterrupted stroke of the last-mentioned punch through the die means associated therewith, means for replenishing fluid lost on each side of said piston in the closed fluid circuit, the lost fluid on either side of said piston in the closed fluid circuit resulting in an unbalancing of the stroke of said piston, said fluid replenishing means including a pair of fluid displacement pump devices, one pump device being directly connectable to a portion of the fluid circuit on one side of said piston and the other displacement pump being directly connectable to the portion of the fluid circuit on the other side of said piston, separate valve means for fluidly connecting each pump device separately and directly to a different side of said yoke-type drive means simultaneously with connecting a given pump device to a fluid deficient portion of the fluid circuit so as to separately activate each of said pump devices, a separate sensor means on each side of the apparatus and activated by a given overstroked punch for selectively and separately operating one of said valve means so as to connect a selected one of said pump devices to one side of said yoke-type drive means simultaneously with connecting said last-mentioned pump device to a fluid deficient portion of the closed fluid circuit.
 9. An apparatus as set forth in claim 8 in which said yoke drive means includes a drive piston at each side of the yoke-type drive means, each drive piston being in direct contact with the fluid in a given portion of said closed fluid circuit in order to effect reciprocation of the fluid in the closed circuit and reciprocation of said actuating piston.
 10. An apparatus as set forth in claim 9 in which each displacement pump device includes a pump piston which has a smaller diameter than a drive piston attached to said yoke-type drive means.
 11. An apparatus as set forth in claim 8 in which said sensor means are electromagnetic sensor means.
 12. An apparatus as set forth in claim 8 including oppositely disposed solenoid means operated by a sensor means for controlling each of said valve means and keeping said valve means in a ready condition at all times.
 13. An apparatus as set forth in claim 8 including a further valve means for isolating one pump device from the fluid circuit when the other pump device is operating. Pg,22
 14. An apparatus for forming a deep drawn seamless can body provided with a bottom and sidewall formed integrally therewith and comprising a closed fluid circuit, a piston means mounted in one portion of said fluid circuit, at least one separate forming punch means secured to each of the opposing sides of said piston means, yoke means located in another portion of said circuit for cyclically activating portions of the fluid in said closed fluid circuit in order to actuate said piston means so as to alternately urge first one of said punch means in a single uninterrupted stroke of the punch means through a die means associated therewith and then an opposing punch means in a single uninterrupted stroke of the last-mentioned punch means through the die means associated therewith, means for replenishing fluid lost on one side of said piston means and in a selected portion of the fluid circuit, the said lost fluid on the one side of said piston means causing an unbalanced stroke thereof, said replenishing means including a sensor operatively associated with a punch means for detecting an overstroked punch means upon a fluid deficiency, the improvement comprising a sensor operated valve means for fluidly connecting a fluid pump device directly to a fluid activated portion of said fluid circuit simultaneously with connecting the same pump device to the fluid deficient portion of the fluid circuit whereby said pump device can in rapid fashion supply fluid to the fluid deficient part of the circuit upon the fluid deficiency being detected.
 15. An apparatus as set forth in claim 14 wherein said sensor is an electromagnetic sensor.
 16. An apparatus as set forth in claim 14 including an amplifier means interconnecting said valve means and said sensor for placing said valve means in a ready condition at all times. 